Leaf spring steel?

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Posted · Report post

Hi guys.Got a peice of a pick ups leaf spring at a scrapyard for free the other day.Good steel for making knives?
BB

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Posted · Report post

Oh yeah! Cut off a slice and go to town:D.

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Posted · Report post

Thanks App Man. Any special method youd recomend? I have fooled around with making knives before but have not made one out of spring steel before.
Bb

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Posted · Report post

Hi ya'll.
I'm new here, but saw the post and thought I'd chime in. Blackbeard, you got yourself a sure-nuff piece of knifemaking steel! Leaf spring is usually really good steel. Most leaf springs are made from 5160, which is an excellent blade steel. 5160 is my primary blade steel for just that reason. If you can get a coil spring, and straighten it out, that's usually good steel too. You want to heat a small piece of your steel to orange-hot, quench it in oil (transmission fluid or vegetable oil will work) that's heated to about 90 degrees (you can heat the oil by dropping a heated piece of steel in it before you quench the test piece). Once the test piece is cooled, run a file across it - it will probably slide like it's on glass, which is what you want. If steel gets that hard and resists a file like that, then it's probably good for making knives. Otherwise, if it was me, I'd forge it down to shape using a hammer and an anvil-like object (I say that because a 100# piece of granite will work for an anvil...). If you're going to grind it, or use files to shape it, anneal it first. 5160 is super tough stuff, and is not easy to grind or file. Anneal by heating to orange, and burying in about 2 feet of vermiculite, wood ash or ashes from a bbq grill (make sure there's no charcoal in there or it'll ignite!), or even burying in about 2ft. of dirt. Leave it for at least 6 hrs, if not longer. The longer and slower the steel cools, the easier it is to grind or file on. If it cools too fast, it'll harden up and Hercules wouldn't be able to shape it. If you're really interested in learning how to make knives, get a copy of Wayne Goddard's $50 knife shop. I've been forging for about 6 years and I still use that book as an information source. Any questions, please feel free to email me. Happy knifemaking, dude!:D

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Posted · Report post

Used leaf springs, especially from trucks, can have small fatigue cracks in them. They don't go away when you forge them but inconveniently grow into a major nuisence in the quench. Grind the surface down to shiney metal, try to keep the grinding marks in the long direction and leave the surface as smooth as possible. Then spray it down with a light coat of white spray paint and let it dry. Cracks will show up as little black lines. Bear in mind, some very fine, tight cracks will not show up. You can grind the cracks out, leaving a large shallow basin and then forge the piece without concern about the crack growning. And some springs are only 1040, not 5160.

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Posted · Report post

here's a bowie i finished from carriage spring, same as leaf spring, a while ago

I like leaf springs because you can cut them into smaller pieces or draw them out if you want smaller knives, but the width and thickness of the springs can make for a real big knife. Not to mention they're easy to get!

2203.attach

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Posted · Report post

Scrapyard steel rule: gotta test it as there is no guarentee what it "really" is!

I ran into a microalloy strain hardened spring one time, nearly drove me bats as it would not quench harden; not even in brine!.

Living in an area where the roads can be pretty bad I'd watch out for micro cracked pieces; *but* places that make custom springs will usually give you drops (or sell it to you for scrap price) *and* can tell you what alloy it is to boot!

I had a student who used to work for a company that built ambulence/EMT vehicles and the first thing they did was to take off the brand new springs and junk them, (only milage was from the manufacturer delivery point to the shop where they were re-built.) Sigh had to leave most of my scrap when I moved 1500 miles away.

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Posted · Report post

It went to good homes; when I was doing my big loading party a friend brought over a small dumptruck and anything nobody wanted went up into that for his scrap pile---including the stuff he said he didn't want, just waited till his back was turned and...

We loaded it all on pallets and then the truck was 2 weeks late and everything was out in the thunderstorms while I was 1500 miles away back at work. More rain damage than move damage. Took a flat bed semi + 3 pallets went common carrier cause we ran out of room on the semi.

Don't plan to move again!

I used to give away stuff all the time as I could find it faster than I could use it and so would share the wealth.

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Posted · Report post

Thomas,
I wish I lived nearby. knowlege and stuff, two great tastes taste great together

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Posted · Report post

as Sam said for beginner/intermediate knifemakers leaf springs are great, and in the proffessional market some people can be more picky. Personally I think forged knives are a whole market of their own. Like the Grateful Dead, forged knives have imperfections and are very unique and appeal to certain people. Virgin steel is best used in stock removal and sent away for heat treating; if you're going for a perfect knife, get it perfect in as many ways as you can ;).

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Hello:

I wouldn't recommend using them for anything but practice as mentioned above there can be some serious problems with cracks, add that to the fact that you are swag-ing as far as what it is really...

However I do use them when I run out of cut offs for axe bit/tommahawk edges as the welding will pretty much remove the cracks from the equation...but then again..what do I know anyways???

New 5160 is not all that expensive and as Mr Powers said you can always scrounge automotive spring makers for their "scrap" and get it for pennies a pound usually....


JPH

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Posted · Report post

Pault17; really you don't. The real reason I fled Columbus OH was that a number of wives, husbands and SO's had put a hit out on me for filling their yards and garages with rusty metal and encouraging their opposite numbers to come home grimey and smelling like sulfur.

Now I live where you can see them coming for a couple of day's walk at least and the attach mesquite, goatheads and cactus are always on guard.

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Posted · Report post

Thanks for all the replies guys. Nice knife Julian! Any finish I can use to prevent rust?Or doesnt it rust after being tempered?
Bb

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Posted · Report post

Hi ya'll.
I'm new here, but saw the post and thought I'd chime in. Blackbeard, you got yourself a sure-nuff piece of knifemaking steel!...........................

Thanks for the info Blademaker I appreciate it. Glad to hear the spring steel is suitable for knives. Thanks Ill e-mail if I need help.
Bb

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Posted · Report post

Thanks App man! Cant wait to see your next creations!!
Bb

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Posted · Report post

(Seven years after this post) I tried to press a fuller into a blade I was making out of some two inch by quarter inch leaf spring. Here's the results.

 

post-26673-0-14683100-1407537997_thumb.p

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Posted · Report post

Spring looked to have been ridden hard and put away wet *before* you tried that!

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Posted · Report post

Yes, I even have a texturing hammer for when I want to try and get that look. I don't think the fuller goes with it, tho.

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Posted · Report post

that crack is a real problem. be careful no one uses it.

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Posted · Report post

I wouldn't even make a knife like wall hanger from it, someone years from now might try using it and injure someone.

 

Frosty The Lucky.

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Posted · Report post

OK. I'll pound it into something else.

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Posted · Report post

I'm using some leaf spring in knife making and am aware of the crack problems. What would you recommend as a quench for hardening? Thanks

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Posted · Report post

warm vegetable oil (around 140 deg F)  Or buy real quench oil rated for 5160.

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